>
> The patch mostly looks good to me, thanks.
> I'm not 100% sure about the interface. Can we make the flag interface
> specific?
I'm not 100% sure about making the flag interface specific :) Do you think
there's a use case for both client and server mode ports to be used in
conjunction with each other?
> If I'm not mistaken we currently limit vhost-sock-dir to be under OVS
> rundir. With client mode this is not necessary anymore.
Correct I've fixed this in the next version. Thanks.
> I hope that client will be made the default mode at some point, I think we
> should keep that in mind when considering the interface.
I agree. I think we should wait until at least the QEMU v2.7.0 release though.
> Since we're planning to break compatibility with the dpdk phy naming
> change, maybe we can break compatibility also with vhost ports and add a
> path option.
Ok. So something like this?
ovs-vsctl add-port vhost0
ovs-vsctl set Interface vhost0 options:vhost-path=/tmp/v0.sock
Maybe something for a separate standalone patch?
Thanks,
Ciara
>
> Thoughts?
> Daniele
>
> 2016-08-04 7:09 GMT-07:00 Ciara Loftus <ciara.lof...@intel.com>:
> A new other_config DB option has been added called 'vhost-driver-mode'.
> By default this is set to 'server' which is the mode of operation OVS
> with DPDK has used up until this point - whereby OVS creates and manages
> vHost user sockets.
>
> If set to 'client', OVS will act as the vHost client and connect to
> sockets created and managed by QEMU which acts as the server. This mode
> allows for reconnect capability, which allows vHost ports to resume
> normal connectivity in event of switch reset.
>
> QEMU v2.7.0+ is required when using OVS in client mode and QEMU in
> server mode.
>
> Signed-off-by: Ciara Loftus <ciara.lof...@intel.com>
> ---
> v2
> - Updated comments in vhost construct & destruct
> - Add check for server-mode before printing error when destruct is called
> on a running VM
> - Fixed coding style/standards issues
> - Use strcmp instead of strncmp when processing 'vhost-driver-mode'
>
> INSTALL.DPDK-ADVANCED.md | 27 +++++++++++++++++++++++++++
> NEWS | 1 +
> lib/netdev-dpdk.c | 31 +++++++++++++++++++++++--------
> vswitchd/vswitch.xml | 13 +++++++++++++
> 4 files changed, 64 insertions(+), 8 deletions(-)
>
> diff --git a/INSTALL.DPDK-ADVANCED.md b/INSTALL.DPDK-ADVANCED.md
> index f9587b5..a773533 100755
> --- a/INSTALL.DPDK-ADVANCED.md
> +++ b/INSTALL.DPDK-ADVANCED.md
> @@ -483,6 +483,33 @@ For users wanting to do packet forwarding using
> kernel stack below are the steps
> where `-L`: Changes the numbers of channels of the specified network
> device
> and `combined`: Changes the number of multi-purpose channels.
>
> + 4. Enable OVS vHost client-mode & vHost reconnect (OPTIONAL)
> +
> + By default, OVS DPDK acts as the vHost socket server and QEMU the
> + client. In QEMU v2.7 the option is available for QEMU to act as the
> + server. In order for this to work, OVS DPDK must be switched to
> 'client'
> + mode. This is possible by setting the 'vhost-driver-mode' DB entry to
> + 'client' like so:
> +
> + ```
> + ovs-vsctl set Open_vSwitch . other_config:vhost-driver-mode="client"
> + ```
> +
> + This must be done before the switch is launched. It cannot sucessfully
> + be changed after switch has launched.
> +
> + One must also append ',server' to the 'chardev' arguments on the
> QEMU
> + command line, to instruct QEMU to use vHost server mode, like so:
> +
> + ````
> + -chardev
> socket,id=char0,path=/usr/local/var/run/openvswitch/vhost0,server
> + ````
> +
> + One benefit of using this mode is the ability for vHost ports to
> + 'reconnect' in event of the switch crashing or being brought down.
> Once
> + it is brought back up, the vHost ports will reconnect automatically
> and
> + normal service will resume.
> +
> - VM Configuration with libvirt
>
> * change the user/group, access control policty and restart libvirtd.
> diff --git a/NEWS b/NEWS
> index 9f09e1c..99412ba 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -70,6 +70,7 @@ Post-v2.5.0
> fragmentation or NAT support yet)
> * Support for DPDK 16.07
> * Remove dpdkvhostcuse port type.
> + * OVS client mode for vHost and vHost reconnect (Requires QEMU 2.7)
> - Increase number of registers to 16.
> - ovs-benchmark: This utility has been removed due to lack of use and
> bitrot.
> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
> index 7692cc8..39c448b 100644
> --- a/lib/netdev-dpdk.c
> +++ b/lib/netdev-dpdk.c
> @@ -136,7 +136,8 @@ BUILD_ASSERT_DECL((MAX_NB_MBUF /
> ROUND_DOWN_POW2(MAX_NB_MBUF/MIN_NB_MBUF))
> #define OVS_VHOST_QUEUE_DISABLED (-2) /* Queue was disabled by
> guest and not
> * yet mapped to another queue. */
>
> -static char *vhost_sock_dir = NULL; /* Location of vhost-user sockets */
> +static char *vhost_sock_dir = NULL; /* Location of vhost-user sockets */
> +static uint64_t vhost_driver_flags = 0; /* Denote whether client/server
> mode */
>
> #define VHOST_ENQ_RETRY_NUM 8
> #define IF_NAME_SZ (PATH_MAX > IFNAMSIZ ? PATH_MAX : IFNAMSIZ)
> @@ -833,7 +834,6 @@ netdev_dpdk_vhost_user_construct(struct netdev
> *netdev)
> struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
> const char *name = netdev->name;
> int err;
> - uint64_t flags = 0;
>
> /* 'name' is appended to 'vhost_sock_dir' and used to create a socket in
> * the file system. '/' or '\' would traverse directories, so they're not
> @@ -856,14 +856,17 @@ netdev_dpdk_vhost_user_construct(struct netdev
> *netdev)
> snprintf(dev->vhost_id, sizeof(dev->vhost_id), "%s/%s",
> vhost_sock_dir, name);
>
> - err = rte_vhost_driver_register(dev->vhost_id, flags);
> + err = rte_vhost_driver_register(dev->vhost_id, vhost_driver_flags);
> if (err) {
> VLOG_ERR("vhost-user socket device setup failure for socket %s\n",
> dev->vhost_id);
> } else {
> - fatal_signal_add_file_to_unlink(dev->vhost_id);
> - VLOG_INFO("Socket %s created for vhost-user port %s\n",
> - dev->vhost_id, name);
> + if (!(vhost_driver_flags & RTE_VHOST_USER_CLIENT)) {
> + /* OVS server mode - add this socket to list for deletion */
> + fatal_signal_add_file_to_unlink(dev->vhost_id);
> + VLOG_INFO("Socket %s created for vhost-user port %s\n",
> + dev->vhost_id, name);
> + }
> err = netdev_dpdk_init(netdev, -1, DPDK_DEV_VHOST);
> }
>
> @@ -917,7 +920,8 @@ netdev_dpdk_vhost_destruct(struct netdev
> *netdev)
> struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
>
> /* Guest becomes an orphan if still attached. */
> - if (netdev_dpdk_get_vid(dev) >= 0) {
> + if (netdev_dpdk_get_vid(dev) >= 0
> + && !(vhost_driver_flags & RTE_VHOST_USER_CLIENT)) {
> VLOG_ERR("Removing port '%s' while vhost device still attached.",
> netdev->name);
> VLOG_ERR("To restore connectivity after re-adding of port, VM on
> socket"
> @@ -927,7 +931,8 @@ netdev_dpdk_vhost_destruct(struct netdev
> *netdev)
>
> if (rte_vhost_driver_unregister(dev->vhost_id)) {
> VLOG_ERR("Unable to remove vhost-user socket %s", dev->vhost_id);
> - } else {
> + } else if (!(vhost_driver_flags & RTE_VHOST_USER_CLIENT)) {
> + /* OVS server mode - remove this socket from list for deletion */
> fatal_signal_remove_file_to_unlink(dev->vhost_id);
> }
>
> @@ -3181,6 +3186,7 @@ dpdk_init__(const struct smap *ovs_other_config)
> int err = 0;
> cpu_set_t cpuset;
> char *sock_dir_subcomponent;
> + const char *val;
>
> if (!smap_get_bool(ovs_other_config, "dpdk-init", false)) {
> VLOG_INFO("DPDK Disabled - to change this requires a restart.\n");
> @@ -3211,6 +3217,15 @@ dpdk_init__(const struct smap
> *ovs_other_config)
> } else {
> vhost_sock_dir = sock_dir_subcomponent;
> }
> + val = smap_get(ovs_other_config, "vhost-driver-mode");
> + if (!val || strcmp(val, "client")) {
> + /* default case */
> + vhost_driver_flags &= ~RTE_VHOST_USER_CLIENT;
> + VLOG_INFO("OVS server mode (QEMU client mode) selected for
> vHost");
> + } else {
> + vhost_driver_flags |= RTE_VHOST_USER_CLIENT;
> + VLOG_INFO("OVS client mode (QEMU server mode) selected for
> vHost");
> + }
>
> argv = grow_argv(&argv, 0, 1);
> argc = 1;
> diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
> index 63f0d89..41807b3 100644
> --- a/vswitchd/vswitch.xml
> +++ b/vswitchd/vswitch.xml
> @@ -299,6 +299,19 @@
> </p>
> </column>
>
> + <column name="other_config" key="vhost-driver-mode"
> + type='{"type": "string", "enum": ["set", ["server",
> "client"]]}'>
> + <p>
> + Specifies which mode OVS will use for vHost. In 'server' mode, OVS
> + creates and destroys the vHost User sockets. In 'client' mode, OVS
> + attaches to sockets created by QEMU.
> + </p>
> + <p>
> + Defaults to 'server' mode. Changing this value requires restarting
> + the daemon.
> + </p>
> + </column>
> +
> <column name="other_config" key="n-handler-threads"
> type='{"type": "integer", "minInteger": 1}'>
> <p>
> --
> 2.4.3
>
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> dev mailing list
> dev@openvswitch.org
> http://openvswitch.org/mailman/listinfo/dev
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